Electromagnetic pendulum drive



Aug. 6, 1963 R. w. REICH ELECTROMAGNETIC PENDULUM DRIVE Filed Jan. 6.1959 INVENTOR. ROBERT WALTER RE/CH WWW United States Patent 3,100,278ELECTROMAGNETIC PENDULUM DRIVE Robert Walter Reich, Rotaclrerstrasse Z,Freiburg irn Breisgau, Germany Filed Jan. 6, 1959, Ser. No. 785,197Claims priority, application Germany Jan. 10, 1958 9 Claims. ill.318-428) The invention relates to an electronic working arrangement forclocks, chronometers and time-signal transmitting apparatus.

All the hitherto known working arrangements for clocks with tubes andtransistor circuit schemes are based on the known principle of electricclocks with contacts. The transistor, for example, serves in all circuitschemes merely as substitute for the electric switch with contacts. Thecontact-making for producing the working impulse is effected byenergizing the basic circuit of the transistor. By a suitable coilarrangement and the employment of permanent magnets a potential impulseis induced on the magnet passing into and out of a coil and thispotential impulse excites the timebase emitter circuit so that thetransistor becomes conductive.

Such circuit arrangements, as is generally known, are open to objectionswhich practically outweigh the advantages of transistor circuits. Inparticular, it is the holding current in the circuit arrangement and theexceptionally great dependency upon tempera-ture which have adisadvantageous effect on the construction of clocks and on their use.The bolding current represents a loading of the source of current whichis many times that of the working current. Through the dependency upontemperature, the accuracy of the clocks is reduced and, when dependencyupon temperature also exists in the case or" the mechanical parts, thisreduction in accuracy is further augmented by the amount which emanatesfrom the transistor circuit. Compensation is not possible because theinaccuracy for the mechanical oscillating system and the inaccuracy fromthe transistor circuit add up. Moreover, the clock construction withcoils and permanent magnets which swing in the coils also possess manyother disadvantages. Primarily the unattractive appearance of the wholearrangement restricts considerably the utility value of clock-s in thecase of the known system with cont-actless control for driving andenergizing coils and permanent magnet in pendulum oscillation.Consequently the object of my invention is to produce an electronicsarrangement for clocks, chronometers and time-signal transmittingapparatus, which is entirely independent of temperature, has anextraordinarily low cur-rent consumption, works extremely accurately andis simple to regulate. Finally the electronic arrangement according tomy invention is intended to make it possible to produce clocks which areVery attractive in appearance and very practical.

These objects are attained by the new electronic Working arrangement forclocks, chronometers and time-signal transmitting apparatus, with asource of current, gear train, mechanical oscillating system andtransistors or tubes, which arrangement is characterized in that anoscillator circuit arrangement with coils and/or condensers is blockedin the inoperative position by uncoupling by means of metal covers orplates and is released by coupling effected by the swinging over of apendulum magnet, preferably with only one pole, in the direction towardsthe coils, whereby a sequence of impulses composed of like-poledneedle-shaped impulses with high voltage in the frequency of theoscillator circuit arrangement, periodically drives the mechanicaloscillating system by repelling and attracting the swinging permanentmagnet.

The invention will be better understood from the fol- Bib-@278 PatentedAug. 6, 1963 ice lowing explanation thereof with the aid of theaccompanying drawings, in which FIG. 1 shows schematic-ally a first formof construction of the working arrangement according to the invention;

FIG. 2 shows another form of construction of the invention wherein asquegging oscillator circuit serves as osci-laltor circuit;

FIG. 3 is yet another schematic representation of a form of constructionof the invention similar to that illustrated in FIG. 2;

FIG. 4 is a schematic illustration of another form of construction ofthe invention which is particularly suitable for .stepby-step mechanismsand FIG. 5 finally shows schematically another .form of construction ofthe invention which is particularly suitable in the event where onlyvery small permanent magnet-s can be used as swinging magnets.

As these figures will now be described in detail, and particularlyFIGURE 1, it is pointed out that in the switching arrangements accordingto the invention the periodical drive is effected by an oscillator in aspecial circuit arrangement.

In FIG. 1 is shown a transistor blocking oscillator including atransistor 1 having a first coil 2 connected across its base emitterpath and having a sewnd coil 3 connected to its collector. A capacitor11 shunts coil 3, and a battery 10 connects capacitor 11 and coil 3 tothe emitter of the transistor.

Coils 2 and 3 are disposed in coaxial relationship and a cup-shapedshield 4 made of this brass or aluminum is disposed between the coilsthus decoupling them by magnetic shielding.

Shield 4 decouples coils 2 and 3 to such an extent, that the oscillatorwill not run. There is further provided a pendulum in form of apermanent magnet 5, the north pole of which swings over the open end ofcoils Z and 3 and cup 4. When magnet 5 is in or near the positionindicated, the shielding effect of cup 4 is partially over-ridden by thecoupling ellect exerted by magnet 5 with respect to the coils.

Whenever magnet 5 is deflected from the position illustrated (see arrows5'), the coupling eliect vanishes and the oscillator is blocked again.

Magnet 5 exhibits another effect in that it induces a voltage in coil2., for example when it approaches the illustrated zero position. Thisvoltage opens transistor 1 and thus starts the oscillator.

A third function of magnet 5 is to serve as a passive impeller. Wheneverthe oscillator is opened, the current permitted to flow through coil 3is determined by the direction of the collector current; the amplitudeof the current through coil 3 is determined bythe feed back action ofcoil 2 being, on one hand now inductively coupled to coil 3, and beingconnected to base and emitter of transistor 1. This feed back actionproduces needle sharp pulses of one polarity. Current pulses of oppositepolarity are produced in coil 3, but they are of considerable lesseramplitude, because in this opposite direction, the now blocked emitter:base path serves as an open circuit for the coil 2, being a secondarywinding of the existing transformer action between coils 2 and 3. Theneedle pulses impel magnet 5. The frequency of the oscillator and theamplitude of the oscillations are solely dependent upon the circuitconstants of the oscillator. Due to the magnetic accumulation, aninduction current is produced in the working coil (2 or 3) at theswitching in and out of each swing and results in an increase ofvoltage. Under given conditions in the case of clock constructions thisincrease in voltage amounts to about 30 to 50 times. For the drive ofsuch clocks a source of current with a working potential of about 1 to 2volts is suflicient and the potential occurring on the driving coilattains about 30 to 50 volts. The frequency of the oscillator lies inthe order of magnitude between 3,000 and 10,000 cycles. As the permanentmagnet 5 swings over the coil arrangement, impulses are, as stated,released in the order of about to impulses at a base frequency of 3,000to 10,000 cycles. The oscillation pull itself, due to. the permanentmagnet 5 of which only one pole (the N-pole in FIG. 1), becomesoperative for the coupling, is already in the form "of needle-shapedimpulses which, read on one side of the zero point, have very highamplitudes of 30 to 50 times the value of the basal voltage. On theother side of the zero point relatively low impulse peaks are certainlyproduced but in relation to the needle-shaped high impulses scarcelybecome apparent. The cscillographic diagram shows an oscillation pullsimilar to the known diagram in the case of a direct current transformerin transistor circuit arrangement with diode introduced for suppressinga halfwave. The magnetic coupling thus produced in the arrangementaccording to the invention over a permanent magnet with only one pole,results in an oscillation diagram of like-directed, needle-shapedimpulses which, in the driving coil, build up a magnetic field whichrepels the magnet. In brushing over the driving coil the magnet 5 itselfis therefore repelled. This magnet 5 is now arranged in a swingingpendulum or a rotary pendulum or in a balance-like construction, so thatthe oscillating system receives periodic impulses. These periodicimpulses are dependent in number and magnitude upon the constants of theoscillating circuit of the transistor system. It is easily possible toprovide several permanent magnets in suitable arrangements, for example,in the case of'rotary pendulum clocks, in the mechanical oscillatingstructure. In this Way a corresponding swing pull is produced inswinging over each permanent magnet, causing a driving impulse for thefurther rotation.

The circuit illustrated in FIG. 2' contains all the elements of thecircuit of FIG. 1. Additionally, there is a resistor 28 inserted inseries circuit connection with coil 2 for adjustment of the internalimpedance of the oscillator. A rectifier 6 short-circuits those voltagesinduced in coil 5 which do not open the transistor 1. Furthermore, inFIG. 2 is shown a balance Wheel 27, biased by a spring 26 in the usualmanner while a permanent magnet oscillates with this balance andperforms the same function as magnet 5 does in the device shown in FIG.5.

In the device shown in FIG. 3, the capacitor 11 of FIGS. 1 and 2 isreplaced by a capacitor 31 connected across coil 2, and a blocking diode36 is connected in series circuit connection to L-C circuit 2-31. Thereis also provided a resistor 37 connected in series with diode 36.

There is a rotary pendulum or balance like structure including a shaft38 rotatably supported in stationary bearings 32 and '33. There is abalance spring 39 connected to the shaft for recoiling a balance wheel34. Balance wheel 34 supports small permanent magnets 35 and 35'performing a similar function as magnets 25 and 5 previously described.

It is evident that the oscillator circuit can also be constructed withonly one coil as self-induction and a condenser. The self-induction coilis this case the driving coil. When using two or more coils the mannerin which these are arranged is immaterial. They can be arrangedside-by-side, one behind the other, one within the other or in someother fashion. The only important factor is that the permanent magnetestablishes a coupling between the coils and that normally uncoupling orturning out by metallic screening occurs in inoperative position. It isvery advantageous to accommodate the whole arrangement in the base of aclock so that it is entirely out of sight. The permanent magnet ormagnets can also be built in the swinging or rotating pendulum so as tobe completely invisible. As these magnets do not swing in any coils butonly over them, it is not necessary to take into consideration theguiding of the pendulum. It is also possible to regulate the clock byvarying the distance of the pendulum from the driving coils, which isnot possible in the case of arrangements with swing-in magnets and whenusing a transistor system as contactless switch. For example, if thepermanent magnet is accommodated in a spherical or conical pendulum sothat the screw. thread can be provided directly on the housing of thependulum. Also by providing a screw-thread on the pendulum rod it ispossible, by merely turning the pendulum housing, to effect regulationby changing the distance of the permanent magnet. Similarly, this can beeifected in the case of rotary pendulum clocks by raising and loweringthe pendulum balls in which the permanent magnets are fitted. Any lcnowncircuit arrangement can be employed as oscillator system, such as, forexample, (the Meacham bridge, or the Hartley circuit, or a multiplevibrator circuit or a blocking oscillator circuit as shown in FIGURE 2,or any other suitable circuit arrangement for producing oscillations inthe frequency range up to about 10,000 cycles per second. The circuitarrangement is built-up on the basic principle so that .the startinginof oscillation is effected by the coupling via permanent magnet ormagnets. In inoperative position, provision is made that no feed currentflows by suitably uncoupling.

For very small clocks very advantageous constructional possibilities areobtained by using simple oscillating circuit arrangements with only onetransistor of miniature size. Both s-tep-by-step switching mechanismsand also mechanisms with mechanical oscillating systems can be built upin balance-like constructions. In the case of a step-by-step switchingmechanism the frequency of the switch-in of the actual oscillatingelement is preferably based on a second. The oscillating circuitarrangement of the oscillator is then so chosen that a basic frequencyof about 3,000 to 10,000 cycles is produced by suitably dimensioning theselfainductance coils or the condensers and that this basic frequencyalways occurs every second. As shown FIGURE 4 the simplest way ofattaining this is by charging a condenser 43 in the base circuit of thetransistor. The condenser 43 is so dimensioned that the charging timeamounts to exactly one second. By connecting up in series a variableresistance 44, the charging time for the condenser can be accuratelyregulated to the value of a second. It is evident that any otherswitching period can be used if the ratio of transmission in the trainof gears is appropriately chosen. In the case of a balance-type of clockmovement, either the balance itself is constructed as a disc-shapedpermanent magnet or a suitable small permanent magnet is fitted on thebalance (see FIG. 3). The only important point is that the permanentmagnet is periodically released by coupling the oscillating process inthe transistor circuit.

By using the above-described control arrangement according to theinvention, very significant advantages are obtained for the constructionof clocks. Dependency upon temperature does not exist at all, becausethere is no holding current dependent upon temperature in the transistorcircuit arrangement. The current consumption is extremely low andamounts to about 10% as compared with the switching arrangements inwhich the transistor acts as contactless switch. Regulation can becarried out in a very simple manner. The clock construct-ion itself canbe performed in any desired manner, because no consideration need bepaid to the electrical setup. As a result clocks of extremely attractiveappearance and very practical design can be produced.

The constructional principle can obviously be applied in a similarmanner for chronometers and for standard time keepers and also fortime-signal transmitters. For standard time keepers a suitable quartz,adjustable by thermostats, can be included in the circuit arrangement.

For chronometers and tirne-signal transmitters, the frequency of theoscillator can be chosen to suit the range of measurement. Formeasurements of fractions of seconds the basic frequency shouldpreferably be chosen as high as possible. This frequency is only limitedby the known transistor characteristics. When using tubes, the basicfrequency can be of any desired height. In certain cases, which mightarise on account of the construction of the clock, the magnetic couplingcannot be effected over one magnet pole but both poles are operative, itis then necessary to cut-out a semi-wave in the current feed to thedriving coil by introducing-a diode in front of the alternating voltagewhich then occurs. 'If, in special cases, only very small permanentmagnets are employed so that the coupling is not strong enough toinitiate an oscillating process with sufliciently high amplitude ofoscillations, a strong reaction is obtained, as shown in FIGURE 5, overa small auxiliary coil 51 which is also arranged on the driving coil 3,and a condenser 52 between the emitter and the base of the transistorl.If, in such a case, there is very low current flux through the drivingcoil, that is if the negative voltage on the base of the transistor hasonly attained a certain yet too low value, the base receives via theauxiliary coil 51 and the condenser 52 a supple: mentary negativevoltage which accelerates considerably the reaction procedure and allowsthe amplitude of the oscillations to rise to the necessary value. Thesecond condenser or capacitor 53 serves a similar function as capacitor43 in FIG. 4.

In the case of clocks with stepaby-step switching mechanism, it isparticularly advantageous to produce by means of a small iron screw witha coating of plastic or some other non-magnetic material on its point,an armature adjustable in distance and on which the permanent magnetpulls itself into inoperative position. In this manner a clock isproduced which runs in any position. During the stepping impulse themagnet is attracted in this case by the driving coil system and in theintervals between the progressive steps the permanent magnet pullsitself again against the iron screw into inoperative position. Thus, aspring or weight of any kind is entirely unnecessary.

It will be understood that this invention is susceptible to modificationin order to adapt it to different usages and conditions, and,accordingly, it is desired to comprehend such modifications within thisinvention as may fall within the scope of the appended claims.

I claim:

1. Impelling system for a clock comprising in combination: a transistoroscillator including two coils disposed for mutual inductive coupling;stationary means disposed between said two coils for decoupling them;and a mechanical oscillator including a permanent magnet with one polethereof oscillating in the vicinity of said coils so as to temporarilycouple them thus overriding the effect of said decoupling means.

2. In an electronic clock having a source of electric energy, thecombination comprising: an electronic oscillator circuit including atransistor and a pair of coils coupled to the transistor for oscillatoroperation, one of said coils being connected to said source of energyand in series with said transistor so that current can only pass in onedirection through said series connected coil; metallic plate means foruncoupling said coils to block said oscillator circuit; and a permanentmagnet constituting a mechanical oscillator and having one of its polesmovable over said coils so as to couple said coils for temporarilyunblocking said oscillator circuit whereby during a short period ofunblocking occurring during each cycle of said mechanical oscillator, aplurality of unidirectional high frequency current pulses are producedin said series connected coil, setting up a unidirectional impellingfield for said permanent magnet.

3. In an electronic clock having a source of electric energy, thecombination comprising: an electronic oscillator circuit inluding atransistor and a pair of coils coupled to the transistor for oscillatoroperation, one of said coils being connected to said source of energyandin series with said transistor so that current can only pass in onedirection through said series connected coil; a metallic plate foruncoupling said coils to block said oscillator circuit; and a pluralityof permanent magnets constituting a mechanical oscillator, magnetshaving one of their respective poles movable over said coils so as tocouple said coils for temporarily unblocking said oscillator circuitwhereby during a short period of unblocking occurring during each cycleof said mechanical oscillator, a plurality of unidirectional highfrequency current pulses are produced in said series connected coil,setting up aunidirectional impelling field for said permanent magnets.

4. In an electronic clock having a source of electric energy, thecombination comprising: an electronic oscillator circuit including atransistor and a pair of coils cow pled to the transistor for oscillatoroperation, one of said coils being connected to said source of energyand in series with said transistor so that current can only pass in onedirection through said series connected coil, a metallic plate foruncoupling said coils to block said oscillator circuit, and a balanceWheel having a permanent magnet mounted thereon and moving therewith,said balance wheel with magnet constituting a mechanical oscillator,with the. magnet having one of its poles movable over said coils so asto couple said coils for temporarily unblocking said oscillator circuitwhereby during a short period of unblocking occurring during each cycleof said mechanical oscillator, a plurality of unidirectional highfrequency current pulses are produced in said series connected coil,setting up a unidirectional impelling field for said permanent magnet.

5. In an electronic clock having a source of electrical energy, thecombination comprising: an electronic oscillator circuit including atransistor and a pair of coils coupled to the transistor for oscillatoroperation, one of said coils being connected to said source of energyand in series with said transistor so that current can only pass in onedirection through said series connected coil; a metallic plate foruncoupling said coils to block said oscillator circuit; a diodeconnected across one of said coils; and a permanent magnet constitutinga mechanical oscillator and having one of its poles movable over saidcoils so as to couple said coils for temporarily unblocking saidoscillator circuit whereby during a short period of unblocking occurringduring each cycle of said mechanical oscillator, a plurality ofunidirectional high frequency current pulses :are produced in saidseries connected coil, setting up a unidirectional impelling. field forsaid permanent magnet.

6. In an electronic clock having a source of electric energy, thecombination comprising: an electronic oscillator circuit including atransistor and a pair of coils coupled to the transistor for oscillatoroperation, one of said coils being connected to said source of energyand in series with the collector-emitter path of said transistor so thatcurrent can only pass in one direction through said series connectedcoil; a metallic plate means for uncoupling said coils to block saidoscillator circuit; a diode connected in series with the base-emittercircuit of said transistor and being poled for current conduction in theemitter current direction; and a permanent magnet constituting amechanical oscillator and having one of its poles movable over saidcoils so as to couple said coils for temporarily unblocking saidoscillator circuit whereby during a short period of unblocking occurringduring each cycle of said mechanical oscillator, a plurality ofunidirectional high frequency current pulses are produce in said seriesconnected coil, setting up a unidirectional irnpelling field for saidpermanent magnet.

7. In an electronic clock having a source of electric energy, thecombination comprising: an electronic oscillator circuit including atransistor and a pair of coils respectively connected to thecollector-emitter circuit and the base-emitter circuit of saidtransistor and being coupledtor oscillator operation, one ofsaid coilsbeing connected to said source of energy and in series with thecollector-emitter path of said transistor so that current can only passin one direction through said series connected coil; metallic platemeans for uncoupling said coils to block said oscillator circuit; and apermanent magnet distant-adjustably positioned with respect to saidcoils and constituting additionally a mechanical oscillator, said magnethaving one of its poles movable over said coils so as to couple saidcoils for temporarily unblocking said oscillator circuit whereby duringa period of unblocking occurring during each cycle of said mechanicaloscillator, a plurality of unidirectional high frequency current pulsesare produced in said series connected coil, setting up a unidirectionalimpelling field for said permanent magnet.

8. In an electronic clock having a sou-roe of electric energy, thecombination comprising: an electronic oscillator circuit including atransistor and a pair of coils coupled to the transistor for oscillatoroperation, one or said coils being connected to said source of energyand in series with said transistor so that current can only pass in oned-inection through said series connected coil;. a metallic plate foruncoupling said coils to block said oscillator circuit; a temperaturestabilized quartz in said oscillator as frequency determining elementthereof; and a permanent magnet constituting a mechanical oscillator andhaving one or its poles movable over said coils so as to couple saidcoils for temporarily unblocking said oscillator circuit whereby duringa short period of unblocking occurring during each cycle of saidmechanical oscillator, a plurality of unidirectional high trequencycurrent pulses are produced in said series connected coil, setting up aunidirectional impelling field for said permanent magnet.

9. In an electronic clock, the combination as set forth in claim 2,comprising, in addition: a third coil and a capacitor connected inseries, said capacitor being connected to the base of said transistor,said coil beinginductively coupled to said pair of coils.

References Cited in the file of this patent UNITED STATES PATENTS2,777,950 Doremus Jan. 15, 1957 2,814,769 Williams Nov. 26, 19572,829,324 Seargent Apr. 1, 1958 2,843,742 Cluwen July 15, 1958 OTHERREFERENCES Gray, Wallace: Principles and Practice of ElectricalEngineering, 6th edition, page 374. McGraw-Hill, New York, 1947.

Terman, F.E.: Electronic and Radio Engineering, 4th edition, page 6 34,FIG. 18-18. McGraw-Hill, New York, 1955.

1. IMPELLING SYSTEM FOR A CLOCK COMPRISING IN COMBINATION: A TRANSISTOROSCILLATOR INCLUDING TWO COILS DISPOSED FOR MUTUAL INDUCTIVE COUPLING;STATIONARY MEANS DISPOSED BETWEEN SAID TWO COILS FOR DECOUPLING THEM;AND A MECHANICAL OSCILLATOR INCLUDING A PERMANENT MAGNET WITH ONE POLETHEREOF OSCILLATING IN THE VICINITY OF SAID COILS SO AS TO TEMPORARILYCOUPLE THEM THUS OVERRIDING THE EFFECT OF SAID DECOUPLING MEANS.